Volcanic plumes continue to billow from the Sangeang Api volcano causing two flights to be cancelled and one delayed affecting holiday makers travelling to Bali on Monday.

Two Jetstar flights out of Perth were cancelled on Monday – the 5.10am flight to Denpasar and the 7.30am flight Singapore via Denpasar – due to the ash from the Sangeang Api volcano off the Indonesian island of Sumbawa.

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A Virgin Australia flight from Brisbane to Denpasar, which was scheduled to depart at 10.10am on Monday, was delayed until midday.

A passenger sleeps in Darwin airport on Satruday after flights were suspended due to the volcanic ash. Photo: Getty Images

Qantas reported there were no cancellations due to the ash plume, but it would keep travellers updated.

Eighteen Jetstar flights, 12 Virgin flights and 10 Qantas flights were cancelled over the weekend due to the volcanic ash from the Sangeang Api volcano.

Although some dispute the impact of volcanic ash, airlines fly cautiously during volcanic activity when it is accompanied by excessive volcanic ash in the atmosphere. The Darwin Volcanic Ash Centre says the most critical effect is caused by melting ash on hot sections of the engine. This causing the ash to fuse like a glass coating over engine components.

Grace Legge, duty forecaster for the Darwin Volcanic Ash Centre, said as of Monday morning the volcano was still letting off low level plumes but these were not headed towards Australia's northern coast.

On the weekend the plumes had headed towards Australia on the back of a jet stream of high and fast winds.

"The initial eruption and two days after that were high level and because of the flow of the atmosphere it caused it to go further up (into flight areas)," Ms Legge said.

She said the volcano was listed as a category three by Indonesia's volcano authority. The highest level is a category four volcano. Ms Legge said Australia had listed it as a "red alert" volcano because of its most recent activity and its likelihood to erupt to a high level again.

The last time Sangeang Api erupted was in 1999, Ms Legge said, but some volcanos in Indonesia continued to "puff away" continuously but they did not cause disruption to flights.

The Smithsonian Museum in the United States categorises the world's volcanos and describes the "Sangeang Api volcano, as one of the most active in the Lesser Sunda Islands, (and it) forms a small 13-km-wide island off the north-east coast of Sumbawa Island".

The Smithsonian describes the volcano as having two large volcanic cones of 1949 metres and 1795 metres high.

Its records show intermittent historical eruptions were first recorded in 1512, but most of the recorded eruptions have occurred in the 20th century.